That unique biological makeup is also known as a "chronotype," or
a predisposition to be a morning person, an evening person, or
somewhere in between. Scientists say your perfect schedule
depends heavily on your specific chronotype.

According to Dr. Michael Breus, a psychologist and sleep
specialist and the author of "The
Power of When," there are four different chronotypes: bear,
wolf, lion, and dolphin. (You can take a quiz to find out which
animal best describes you here.)

As it turns out, I'm a "bear," meaning my internal clock
tracks the rise and fall of the sun.

By and large, the daily routine experiment was a success: Once I
started waking up later and delaying my cup of caffeinated tea
until after 9:30 a.m., I felt more energized and
productive.

At the same time, I completely failed to make one of the
most important changes Breus recommended when we spoke by phone
in July: instituting what he calls the "power-down" hour. About
60 minutes before you go to bed, Breus advises staying off social
media and putting away most digital devices. Instead, you can
read a book or meditate.

It sounded sensible, and pretty easy. But alas, I
couldn't stay off Facebook and Instagram at night.
#chronotypefail.

Recent research on college students suggests that using
digital technology in the hour before bed contributes to
poorer-quality or disrupted sleep. (Interestingly,
other research has found that using social media in general —
not just at night — is linked to sleep
disturbance among young adults.)

Still, breaking the habit of grabbing my iPhone and scrolling
through my newsfeed was harder than it seemed at first.

Maybe it's because the post-dinner period is generally the
first time all day when I don't have an activity planned —
meaning it's the first opportunity I have to be bored. And
boredom may be a key trigger for the Facebook habit.

When we spoke again in August, Breus told me he thinks browsing
photos and updates on Facebook and Instagram stimulates the
release of dopamine, a neurotransmitter related to feelings of
reward and pleasure. So in a way we become "addicted" to that
release, and to social media.

That's why Breus said I'm hardly alone; sticking to the
power-down hour is one of the hardest changes for his bear
patients to make.

At the same time, his experience with patients — especially
bears — has taught him that people really "turn the corner" when
they stop using their digital devices late at night.

One way to make that change easier, Breus said, is simply
to set an alarm for an hour before bed and then move your phone
(and other gadgets) to another room. It might take a few days, if
not a few weeks, to get used to.

"Of the patients that are able to succeed in doing it,"
Breus said, "they say it is one of the most freeing experiences
because they're like, 'Oh my gosh. I'm not tied to my
phone.'"